1// Copyright 2012 The Go Authors. All rights reserved.
2// Use of this source code is governed by a BSD-style
3// license that can be found in the LICENSE file.
4
5#include "textflag.h"
6
7// Called by C code generated by cmd/cgo.
8// func crosscall2(fn, a unsafe.Pointer, n int32, ctxt uintptr)
9// Saves C callee-saved registers and calls cgocallback with three arguments.
10// fn is the PC of a func(a unsafe.Pointer) function.
11TEXT crosscall2(SB), NOSPLIT|NOFRAME, $0
12 SUB $(8*9), R13 // Reserve space for the floating point registers.
13
14 // The C arguments arrive in R0, R1, R2, and R3. We want to
15 // pass R0, R1, and R3 to Go, so we push those on the stack.
16 // Also, save C callee-save registers R4-R12.
17 MOVM.WP [R0, R1, R3, R4, R5, R6, R7, R8, R9, g, R11, R12], (R13)
18
19 // Finally, save the link register R14. This also puts the
20 // arguments we pushed for cgocallback where they need to be,
21 // starting at 4(R13).
22 MOVW.W R14, -4(R13)
23
24 // Skip floating point registers if runtime.goarmsoftfp!=0.
25 MOVB runtime·goarmsoftfp(SB), R11
26 CMP $0, R11
27 BNE skipfpsave
28 // Save VFP callee-saved registers D8-D15 (same as S16-S31).
29 MOVD F8, (13*4+8*1)(R13)
30 MOVD F9, (13*4+8*2)(R13)
31 MOVD F10, (13*4+8*3)(R13)
32 MOVD F11, (13*4+8*4)(R13)
33 MOVD F12, (13*4+8*5)(R13)
34 MOVD F13, (13*4+8*6)(R13)
35 MOVD F14, (13*4+8*7)(R13)
36 MOVD F15, (13*4+8*8)(R13)
37
38skipfpsave:
39 // We set up the arguments to cgocallback when saving registers above.
40 BL runtime·cgocallback(SB)
41
42 MOVB runtime·goarmsoftfp(SB), R11
43 CMP $0, R11
44 BNE skipfprest
45 MOVD (13*4+8*1)(R13), F8
46 MOVD (13*4+8*2)(R13), F9
47 MOVD (13*4+8*3)(R13), F10
48 MOVD (13*4+8*4)(R13), F11
49 MOVD (13*4+8*5)(R13), F12
50 MOVD (13*4+8*6)(R13), F13
51 MOVD (13*4+8*7)(R13), F14
52 MOVD (13*4+8*8)(R13), F15
53
54skipfprest:
55 MOVW.P 4(R13), R14
56 MOVM.IAW (R13), [R0, R1, R3, R4, R5, R6, R7, R8, R9, g, R11, R12]
57 ADD $(8*9), R13
58 MOVW R14, R15